Class: Pump

vertx/pump~ Pump

new Pump(readStream, writeStream)

Pumps data from a ReadStream to a WriteStream and performs flow control where necessary to prevent the write stream from getting overloaded.

Instances of this class read bytes from a ReadStream and write them to a WriteStream. If data can be read faster than it can be written this could result in the write queue of the WriteStream growing without bound, eventually causing it to exhaust all available RAM.

To prevent this, after each write, instances of this class check whether the write queue of the WriteStream is full, and if so, the ReadStream is paused, and a drainHandler is set on the WriteStream. When the WriteStream has processed half of its backlog, the drainHandler will be called, which results in the pump resuming the ReadStream.

This class can be used to pump from any ReadStream to any WriteStream, e.g. from an HttpServerRequest to an AsyncFile, or from NetSocket to a WebSocket.

Parameters:
Name Type Description
readStream module:vertx/streams~ReadStream a ReadStream
writeStream module:vertx/streams~WriteStream a WriteStream
Source:

Methods

bytesPumped() → {number}

Return the total number of bytes pumped by this pump.
Source:
Returns:
the number of bytes pumped
Type
number

setWriteQueueMaxSize(maxSize) → {module:vertx/pump~Pump}

Set the write queue max size to maxSize
Parameters:
Name Type Description
maxSize number the maximum size of the write queue
Source:
Returns:
Type
module:vertx/pump~Pump

start() → {module:vertx/pump~Pump}

Start the Pump. The Pump can be started and stopped multiple times.
Source:
Returns:
Type
module:vertx/pump~Pump

stop() → {module:vertx/pump~Pump}

Stop the Pump. The Pump can be started and stopped multiple times.
Source:
Returns:
Type
module:vertx/pump~Pump